Improvement in piston steam-valves



UNITED STATES PATENT EEIGE.

ROBERT C. GRAY AND VVILLTAM B. BRITTINGHAM, OF LA FAYETTE, IND.

IMPROVEMENT IN PISTON STEAM-VALVES.

Specification forming part of Letters Patent No. 86,067, dated January 19,1869.

To all whom it may concern:

Be it known that we, ROBERT C. GRAY and WILLIAM B. BRITTINGHAM, of La Fayette, in the county of Tippecanoe, in the State of Indiana, have invented a new and useful Improvement in Piston-Valves; and we do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the annexed drawings, making part of this specification, in which- Figure l is a side elevation of the pistonvalve, showing the cam-shaped groove for partially rotating the same, and also the projections upon the ends thereoffor the samepurpose. Fig. 2 is also a side elevation of the piston, showing the steam-ports and the end projections. Fig. 3 is a central sectional elevation, showing the partitions within the steam-chest, the steam-ports within the piston, and the eamshaped groove. Fig. 4 is a transverse seetional elevation, showing the steam-ports leading to the cylinder and their relation to the ports in the piston; also the cam-shaped groove and the pin for rotating the piston. Fig. 5 is a perspective view of the chest, with its induction and eduction pipes and partitions for controlling the admission and emission of the propelling-iiuid. Fig. 6 is a transverse vertical elevation of Fig. l on the line a' thereof, showing the arrangement of the steam-ports and of the cam-groove. Fig. 7 is a transverse section of Fig. 2 on the line y y thereof, which also shows the arrangement of the steam-ports. Fig. 8 is a top view of the valve, showing the arrangement of parts within the chest; and Fig. 9 is a. perspective view of a spring which is used in connection with the projections upon the piston.

Gorrespondin g letters denote corresponding parts in the several figures.

This invention relates to that class of devices which are termed piston-valves, and it consists in a valve constructed with steampassages within it, said passages being arranged in such a manner that the valve will perform the functions of a piston in connection with those of a valve.

The invention further consists in the combination and arrangement of the part-s of which the device is composed, as will be more fully described hereinafter.

A, in the drawings, is a cylinder, which may be of any desired size, and which is closed at its ends, with heads attached thereto in the usual manner, and which is of usual construction in other respects, except that it is provided with a pin or projection, f, upon its inner surface, the oliice of which will be fully explained hereinafter.

B is a piston or valve, which is made to i move steam-tight within cylinder A, and is of sufficient length to admit of the formation within its surface of two or more steam-ports, d d. These ports are made parallel to each other, one of them extending from a point near the left hand of the piston to and opening out of the right-hand end, while the other extends from a point near the right-hand end thereof to and opens out upon the left-hand end thereof. The space between these grooves is of such width, and is so arranged with reference to such grooves and to the induction and eduction ports, that such groove or port in its turn serves as an induction-port to, and an eduetion-port from, its respective end of the cylinder, the change of position necessary to effect this result being effected by means of the pin f, which works within the cam-shaped groove formed upon or within the surfaces of the piston, the arrangement of the ports being clearly shown in Figs. l, 2, 3, and 4.

C is a steam-chest, which is placed upon the cylinder, and held by bolts in any convenient manner. This chest is provided with a partition, g, which divides it into separate compartments, through one of which the propellingfluid is admitted to the cylinder, while through the other it is expelled therefrom. This partition also serves to form the dividing-plate between the steam ports or passages which lead from the chest to the cylinder.

D is a spring, which is to be secured to the inner surface of the cylinder-heads, and in such a position that, as the piston approaches it, the projection a, formed upon either end thereof, shall come in contact with such spring, the action of which will be such as to aid in turning the piston to the extent required to permit it to start upon its return stroke, with the pin f in the portion of cam-groove e which is opposite to that in which it was upon the rst or former movement of the piston. It is believed that this aid to the movement of the piston will only be found to be necessary when the motion of the piston or valve is slow, as, for instance, when water or some other liquid is used as the motor.

E is the induction-pipe, and F is the eduction-pipe.

a a are the projections upon the ends of the piston or valve, which are for the purpose of aiding the movements of the piston. as above described.

b b are the induction-ports, which are arranged one upon either side of the partitions which inclose the eduction-port. They are to be such a distance apart that the camgroove in the piston will cause the one which for the time is acting as the induction-port to come directly under and communicate with the eduction-port upon the return stroke of the valve. c is the eduction-port, which is arranged midwaybetween the induction-ports, as clearly shown in Fig. 8 of the drawings. d d arethe ports or passages which are to be formed in the surface of the valve. e is the cam-shaped groove formed in the surface of the piston, and is so constructed and located as to cause the required amount of rotation in the valve as to produce the effect of bringing each of the ports alternately into communication with the receiving and exhausting ports of the steam-chest. j' is a pin or projection affixed to the interior surface of the cylinder, and which is to project therefrom for a distance sufficient to enable it to enter the camshaped groove in the piston for the purpose of controlling its movements, as above described. rlhis pin may, if preferred, be provided with a friction-roller, which shall work in the groove for the purpose of lessening the amount of friction. g is the partition formed within the steam-chest, and which divides the same into induction and eduction compartments.

We have described this improvement as principally applicable to steam-engines; but it is apparent that it is equally adapted to the use of water, gas, or any other substance which may be used as a motive power, and also that it is peculiarly adapted to the purpose of'a fluid-meter, the drawings showing it as arranged. for that purpose. The only change,

however, which would be required to adapt it to the purposes of a steam-engine would be to place it upon a piston-rod in such a manner that it could rotate sufliciently to change the position of the openings, as above described.

The operation ofthe device is as follows: It being constructed as shown and described, it is to be placed in any proper position, and the steam, air, gas, or water admitted through pipe E, when the substance thus admitted will pass through one of the passages b or b into the port d, and through that to the cylinder A, when it will press upon the piston and drive it to the end .of the cylinder, when the pin f, being in one of the sides of the cam-groove, will, by the action of the piston itself, change the position thereof sufficiently to bring the other port into communication with the eX- haust-passage, thus providing for the alternate reception and discharge of the propelling medium.

Having thus described our invention, what we claim, and desire to secure by Letters Patent, is-

l. The piston-valve B, constructed with ports d d in its outer surface, which ports or passages actalternately as induction and eduction passages, the necessary changes of position being effected by means of a cam-shaped groove formed in the surface of such valve or piston, substantially as shown and described.

2. The combination and arrangement of the ports d d of the valve and the passages b b and c of the cylinder, substantially as shown and described.

3. The combination and arrangement of the projections a a upon the piston and the springs D upon the cylinder-heads, substantially as shown and described.

4. The arrangement of the partitions within the steam-chest, substantially as shown and described.

5. The arrangement of the induction and eduction pipes E and F with reference to the corresponding compartments of the chest, substantially as shown and described.

' G. The combination ,with the cylinder, of the cam-groove within the surface of the piston and the pin or projection upon the interior su rface of the cylinder, substantially as described.

Y In testimony whereof we have signed our Ynames to this specification in the presence of two subscribing witnesses.

ROBT. C. GRAY. W. B. BR-ITTINGHAM.

Witnesses:

JAMES CLARK, JOI-IN OoNNoLLY, Sr. 

